The present invention relates generally to satellite communication systems, and more particularly, to a frequency reuse scheme and data coding structure for use with a high data rate satellite communication system that provides data, voice and video communication between individuals.
The past several decades has seen the development of communications systems that have provided for the real-time distribution of information on a global scale. The development of these global communication systems has evolved along several paths that use either ground-based or satellite-based communication. Satellite-based systems have been employed for many years to distribute voice, data and video signals for global broadcasting of news and sporting events, for example. With the advent of newer high power satellite systems and technology, direct broadcast television systems are available that provide for broadcasting of television signals from up to 100 stations using a single satellite. Individuals install an antenna and a satellite receiver to receive the broadcasts directly by way of the satellite and display them on a television monitor.
To provide for more personal communication or teleconferencing between individuals, companies such as AT&T, for example, have developed a video telephone system that employs a small (3-4 inch) television monitor in combination with a conventional telephone. The video telephone system typically uses fiber optic links to provide a sufficient bandwidth to carry the video and voice signals. However, this type of system does not have enough bandwidth to provide for full motion video.
In order to provide for an even more cost-effective solution to personal telecommunication needs, the assignee of the present has developed a high data rate satellite communication system that provides for the communication and distribution of full motion video, voice and data signals, to provide for personal teleconferencing between individuals. This system is disclosed in U.S. patent application Ser. No. 08/142,524, filed Oct. 21, 1993, entitled "High Data Rate Satellite Communication System", assigned to the assignee of the present invention, the contents of which are incorporated herein by reference. This system comprises a plurality of user terminals (VSATs) that are linked by and that communicate with each other by way of a satellite relay system. A network control center provides command signals that control the satellite relay system and coordinate linking of terminals to each other. The system employs frequency division multiplexing on uplinks from the terminals and the network control center to the satellite relay system. The system employs time division multiplexing on downlinks from the satellite relay system to the terminals and the network control center. However, frequency reuse described herein is independent of the multiplexing scheme used on individual links.
In order to provide for the most efficient bandwidth utilization in this high data rate satellite communication system, and to increase the number of users that may be supported by the system, it was necessary to develop a new frequency reuse technique and data coding structure. Accordingly, it is an objective of the present invention to provide for a frequency reuse scheme and data coding structure for use with a high data rate satellite communication system that provides for the communication of data, voice and video between individuals.